V-rake

ABSTRACT

The V-rake has an elongated tow beam with a front end adapted to be connected to a towing vehicle and a back end fixed to a back section, the back section is supported by a wheel assembly, which may be a set of tandem wheels. The V-rake further includes first and second rake booms each having a front end and a back end pivotally connected to the back section such that the front ends of the booms can be swung between a transport position and an operating position. The front end of each boom has at least one castor wheel for support. The back section is further adapted to controllably change the distance between the back ends of the booms to adjust the width of a resulting windrow. A number of rake wheels are mounted on each of the rake booms on the side of the boom nearest to the tow beam, wherein the rake wheels are adapted to move vertically with respect to the rake boom using a compression spring mechanism. The rake wheel includes a center disk, an outer ring and tines passing through the outer ring with the ends of the tines individually fixed to the center disk, and may further include a windguard.

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 60/654,940 filed Feb. 23, 2005 and Ser. No.60/662,382 filed Mar. 17, 2005.

FIELD OF INVENTION

The present invention relates generally to wheel rakes and moreparticularly to V-rakes.

BACKGROUND OF THE INVENTION

V-rakes have been found to be an effective farm implement for gatheringcut agricultural materials into windrows. The V-rake generally includesa primary frame, with a front end adapted to be hitched to a tractor anda back end. A pair of rake arms, which are pivotally connected at theback end of the primary frame, are controlled such that they may bepositioned adjacent the primary frame in a closed or traveling positionor extended in the form of a V in the opened or raking position. TheV-rake is supported by a number of rolling wheels mounted on the primaryframe and on the rake arms. Further, each rake arm includes a number ofrake wheels, which may be raised when the V-rake is in the travelingposition, and lowered when the V-rake is in the raking position.

Examples of rakes are described in U.S. Pat. No. 4,324,093 issued Apr.13, 1962 to van der Lely et al; U.S. Pat. No. 5,039,528 issued Nov. 19,1971; U.S. Pat. No. 5,199,252 issued on Apr. 6, 1993 to Peeters; U.S.Pat. No. 5,343,643 issued Feb. 27, 1996 to Tonitti; U.S. Pat. No.5,498,271 issued on Feb. 4, 1997 to Peeters; 5,699,045 issued on May 4,1999 to Rowse et al; U.S. Pat. No. 6,220,008 issued April 24 to Rowse etal and US Patent Publication 2004/0063265 published May 6, 2004 toTonutti.

In addition to the description of the basic rakes, these references alsodescribe a variety of rake wheels, as well as control mechanisms foropening and closing the rakes, for raising and lowering the rake wheels,and for adjusting the rake to vary the width of the windrows.

Though these rakes have been in use for some time, it has been foundthat they do not always satisfy the needs of farmers and ranchers inview of their inherent complexity of operation and their weaknesses.This is particularly true where the rake wheels and the springassemblies for controlling the height of the rake wheels are concerned.It has also been found that existing mechanisms for adjusting the widthof the windrow produced by the rake are ponderous.

As an example, prior art rake wheel assemblies include a center diskwith a hub opening and bolt holes by which the rake wheel assembly isattached to a hub. The rake wheel assembly further includes an outerring with a series of holes equally spaced around its circumference forreceiving rake teeth or tines. One end of each tine slides through oneof the holes in the outer ring, while plates that are fixed to thecenter disk by bolts each sandwich the other end of a number of tines.When one of the tines in this rake wheel assembly has to be replaced,the retainer plate has to be removed. When the retainer plate isremoved, all of the tines held by the plate become loose and can thenfall out of the rake wheel assembly. This process can be veryinconvenient, particularly in the field when the rake wheel assembly isin a vertical position.

Further, it has been found that the material being raked has a tendencyto wrap itself on the rake wheel assembly due to the spacing between thetines. Attempts have been made to remedy this situation by attaching apiece of hard plastic to the tines on the outside of the rake wheelassembly, however this is not found to be fully satisfactory.

Therefore there is a need for an improved, reliable and easy to operateV-rake.

SUMMARY OF THE INVENTION

The present invention is directed to a V-rake that has an elongated towbeam with a front end adapted to be connected to a towing vehicle and aback end fixed to a back section, the back section is supported by awheel assembly. The V-rake further includes first and second rake boomseach having a front end and a back end pivotally connected to the backsection such that the front ends of the booms can be swung between atransport position wherein the rake booms are generally parallel to thetow beam and an operating position wherein the booms are positioned at apredetermined angle to the tow beam, using a control mechanism. Thefront end of each boom has at least one castor wheel for support. Anumber of rake wheels are mounted on each of the rake booms on the sideof the boom nearest to the tow beam, wherein the rake wheels are adaptedto move vertically with respect to the rake boom. The back section isfurther adapted to controllably change the distance between the backends of the booms.

In accordance with another aspect of the invention, the back sectioncomprises first and second vertical beams each having lower and upperends and a mechanism connected between the first and second verticalbeams that is adapted to change the distance between the first andsecond vertical beams.

In accordance with a further aspect of the invention, the back sectioncomprises first and second vertical beams each having lower and upperends, the rake booms being pivotally connected to, the vertical beamsbetween their lower and upper ends, a first horizontal beam has one endfixed to the upper end of the first vertical beam and a secondhorizontal beam has one end fixed to the upper end of the secondvertical beam such that the other ends of the horizontal beams arepositioned end to end, and a third horizontal beam positioned adjacentthe first and second horizontal beams, the tow beam being fixedsubstantially to the center of the third horizontal beam. The backsection further includes a control mechanism connected between the thirdbeam and the first and second beams to move the first and second beamsin a direction parallel to the third beam to change the distance betweenthe first and second vertical beams.

In accordance with an alternate aspect of the invention, the backsection comprises first and second vertical beams each having lower andupper ends, a horizontal beam is fixed between the upper ends of thefirst and second vertical beams, and first and second pivot boxes, whicheach have a predetermined width between one side and another side of thepivot box. The one side of the first pivot box is pivotally connected tothe first vertical beam between the lower and upper ends and the firstrake boom is pivotally connected to the other side of first pivot box;similarly the one side of the second pivot box is pivotally connected tothe second vertical beam between the lower and upper ends and the secondrake boom is pivotally connected to the other side of second pivot box.A pivot box control mechanism is adapted to move the other sides of thepivot boxes towards and away from one another to change the distancebetween the back ends of the booms. The pivot box control mechanism maycomprise a horizontal control beam fixed between the first and secondvertical beams and-below the horizontal beam, a sleeve slidably mountedon the horizontal control beam, first and second linkages pivotallyconnected between the sleeve and the other sides of the of the pivotboxes and a hydraulic cylinder connected between the sleeve and the towbeam to control the movement of the sleeve along the horizontal controlbeam.

In accordance with another aspect of the invention, the back sectionwheel assembly includes a first wheel rotatably fixed to the lower endof the first vertical beam and a second wheel rotatably fixed to thelower end of the second vertical beam. Alternately, the wheel assemblymay include a first set of tandem wheels pivotally fixed to the lowerend of the first vertical beam and a second set of tandem wheelspivotally fixed to the lower end of the second vertical beam. Each setof tandem wheels has a wheel carriage and a pair of wheels mounted byaxles onto the carriage such that the wheels are in parallel andstaggered front to back relative to one another, wherein the front wheelis positioned on the inside of the V-rake and the back wheel ispositioned on the outside of the V-rake. The carriage is pivotally fixedto the vertical beam at a pivot point, wherein a distance between thepivot point and the axle of the front wheel is greater than a distancebetween the pivot point and the axle of the back wheel.

In accordance with a further aspect of the invention, the rake wheelsare connected to the rake booms by rake wheel arms, which are controlledby spring assemblies that permit the wheels to move vertically withrespect to the rake boom.

In accordance with a specific aspect of the invention, the springassembly comprises a compression spring having first and second ends, aplug fixed to the first end of the spring, an insert fixed to the secondend of the spring, the insert has an arm extending from it. A rod thathas a first end and a second end is positioned within the compressionspring wherein the first end is fixed to the plug and the second endextends out of the second end of the spring through the insert, suchthat the insert slides freely on the rod. The second end of the rod isadapted to be connected to a mechanism to control its movement. Thespring assembly further includes an arm that has first and second ends,the first end is fixed to the rake wheel arm and the second end ispivotally connected to the insert arm, whereby the compression springpermits the rake wheel to move vertically to follow a terrain contour.

In accordance with another aspect of the invention, the rake wheelcomprises a center disk having a predetermined radius and adapted to bemounted on a hub, a number of rake tines and an outer ring having asubstantially greater radius then the center disk and having holes atleast equal to the number of rake tines. The holes In the outer ring arespaced about and passing radially through the outer ring, whereby eachof the tines is positioned in a hole in the outer ring with one end ofeach tine fixed to the center disk. The center disk may have holes atleast equal in number to the rake tines spaced about its periphery forreceiving fasteners to individually fix the tines to the center disk.

In accordance with a further specific aspect of the invention, the rakewheel includes a windguard positioned between the center disk and theouter ring. The windguard consists of an annulus having an outer radiusapproximately equal to the radius of the outer ring and an inner radiussmaller then the radius of the center ring so as to overlap with thecenter ring. The inner periphery of the annulus has holes that matchwith the holes in the center disk, and the outer periphery of theannulus has tabs with holes that match with some of the holes in theouter ring, the tabs are substantially perpendicular to the surface ofthe annulus, whereby rake tines are located in the outer ring holes andmatching tab holes. The windguard may be made from a light gaugegalvanized metal with stamped indentations.

Aspects and advantages of the invention, as well as the structure andoperation of various embodiments of the invention, will become apparentto those ordinarily skilled in the art upon review of the followingdescription of the invention in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein:

FIG. 1 illustrates in top view one embodiment of the V-rake while in theopen position in accordance with the present invention;

FIG. 2 illustrates in top view the V-rake of FIG. 1 while in the closedposition;

FIG. 3 illustrates the V-rake of FIG. 1 in side view;

FIG. 4 illustrates in top view another embodiment of the V-rakepositioned to produce a wide windrow;

FIG. 5 illustrates in top view the V-rake of FIG. 4 positioned toproduce a narrow windrow;

FIG. 6 illustrates in-top view a further embodiment of the V-rakepositioned to produce a wide windrow;

FIG. 7 illustrates in top view the V-rake of FIG. 6 positioned toproduce a narrow windrow;

FIG. 8 illustrates in top view the V-rake of FIG. 6 in the transportposition;

FIG. 9 illustrates the V-rake of FIG. 6 in side view;

FIG. 10 illustrates the V-rake of FIG. 6 in side view with mounted rakewheels;

FIG. 11 illustrates a V-rake castor in top view;

FIG. 12 illustrates the V-rake castor of FIG. 11 in side view;

FIG. 13 illustrates the mechanical adjustment mechanism for a wheel liftrod;

FIG. 14 illustrates in side view a connection between a rake boom and arake boom extension;

FIG. 15 illustrates in top view the connection between a rake boom and arake boom extension of FIG. 14;

FIG. 16 illustrates in side view a tension spring assembly for rakewheels in accordance with the present invention;

FIG. 17 illustrates in top view the tension spring assembly of FIG. 16;

FIG. 18 illustrates in side view a compression spring assembly for rakewheels in accordance with the present invention;

FIG. 19 illustrates one embodiment of a back section for a V-rake inaccordance with the present invention;

FIG. 20 illustrates another embodiment of a back section for a V-rake inaccordance with the present invention as seen from the back of theV-rake;

FIG. 21 illustrates a pivot box for the back section of FIG. 20;

FIG. 22 illustrates in side view a windrow width control mechanism;

FIG. 23 illustrates in top view the windrow width control mechanism ofFIG. 22;

FIG. 24 illustrates a tandem wheel assembly for the V-rake;

FIG. 25 illustrate a rake wheel assembly in accordance with the presentinvention for the right side of a V-rake;

FIG. 26 illustrate a rake wheel assembly in accordance with the presentinvention for the left side of a V-rake;

FIGS. 27, 28 and 29 illustrate the assembling procedure for the wheelrake assembly.

DETAILED DESCRIPTION

A V-rake has a pair of rake wheel booms on which rake wheels aremounted, and the size of the V-rake is normally identified by the numberof rake wheels that are mounted on the rake wheel booms. For instance,an 8-wheel rake has four rake wheels on each boom, a 10-wheel rake hasfive rake wheels on each boom, and so on. In order to simplify themanufacturing process for V-rakes while at the same time providing avariety of V-rake sizes, V-rakes having 8, 12 and 16 rake wheels use thesame main boom as the V-rakes having 10, 14, and 18 rake wheels, howeverthe booms are each lengthened by a boom extension on which one rakewheel is mounted. However, this type of modular construction isdescribed by way of example only, and other boom arrangements are withinthe scope of the present invention.

With reference to the drawings, three V-rake arrangements, namely V-rake10, V-rake 110, and V-rake 210, will be described. FIGS. 1 and 2illustrate a top view of V-rake 10, which is a 14-wheel rake, in theopen or operating position and in the closed or transport position,respectively and FIG. 3 illustrates a side view of V-rake 10. However,in order to simplify the drawing,.the rake wheels are not shown on FIG.3. FIGS. 4 and 5 illustrate top views of an open V-rake 110, which is a16-wheel rake. The V-rake booms in FIG. 4 are positioned to form a widewindrow and the V-rake booms in FIG. 5 are positioned to form a narrowwindrow. FIGS. 6 and 7 illustrate top views of V-rake 210, which is an18-wheel rake. The V-rake booms in FIG. 6 are positioned to form a widewindrow and the V-rake booms in FIG. 7 are positioned to form a narrowwindrow. FIG. 8 illustrates a closed 18-wheel rake in top view, andFIGS. 9 and 10 illustrate the 18-wheel rake in side view with andwithout the rake wheels respectively. In order to maintain clarity inthe description of the various V-rakes, components common to all of theV-rakes with be identified by the same reference numbers.

V-rake 10, 110 and 210 includes a frame structure 11 having a tow beam12 fixed at the back end to a back section 13. The tow beam 12 includesa main beam section 14 and a goose neck section 15, which is terminatedby a hitch tongue 16. The main beam section 14 and the goose necksection 15 may be made from a single square or rectangular beam, or asshown in FIGS. 3 and 9, the main beam section 14 with the goose necksection 15 may be made from a beam 17 and a truss support 18 which areconnected together by truss plates 19 in order to strengthen the towbeam 12 without adding undue weight.

The back section 13, two embodiments of which will be described indetail in conjunction with FIGS. 19 to 23, is supported by a pair ofwheel assemblies 21, 22. Further, the V-rake 10, 110, 210 includes rakebooms 23, 24 that are pivotally connected to the rear section 13, whichpermits the booms 23, 24 to pivot in a horizontal plane so that theV-rake 10, 110, 210 may be opened and closed. Rake wheels 25 and 26 aremounted on the inside of the rake booms 23 and 24 respectively usingwheel arms 27 and 28.

V-rake 10 in FIGS. 1 to 3, which is a 14-wheel rake includes booms 23,24 of the type that may also be used for a 12-wheel rake, but that isextended in length using single wheel rake boom extensions 31, 32. TheV-rake 110 in FIGS. 4 and 5, which is a 16-wheel rake includes booms 23,24 without any extensions. However in view of the length of the booms23, 24 in V-rake 110, which can cause stresses in the booms 23, 24 asthe V-rake 110 tries to follow the contour of the terrain, the booms 23,24 may be be made up of sections 23A, 23B and sections 24A, 24B, whichare hinged together using knuckle hinges 100. Six rake wheels aremounted on each of the main boom sections 23A, 24A, while two rakewheels are mounted on each of the hinged boom sections 23B, 24B. Thehinge 100 mechanism is described in greater detail in conjunction withFIGS. 14 and 15. V-rake 210 illustrated in FIGS. 6 to 10, is an 18-wheelrake which includes booms 23, 24 having main boom sections 23A, 24A andhinged boom sections 23B, 24B as for V-rake 110, however the booms 23,24 are extended in length using a single-wheel rake boom extension 31,32.

The V-rake 10, 110, 210 would normally be supported by free wheelingwheels. As shown in FIGS. 3 and 9, the rear wheel assemblies 21, 22 maybe fixed to the rear section 13 to support the back of the V-rake 10,110, 210. In addition, the rake booms 23, 24 are further extended bycastor extensions 33, 34, on which are mounted castor wheels 35, 36. Thecastor extensions 33,34 project towards the front and inside of theV-rake 10, 110, 210 so that the castor wheels 35, 36 are positioned infront of the rake wheels 25, 26 to provide stability to the rake booms23, 24. In V-rakes 10, 110, which are quite long, it is preferable tohave a further set of castor wheels 37, 38 mounted on the rake booms 23,24 using brackets 39, 40. With the addition of rake extensions 31, 32 asin the V-rake 210 illustrated in FIG. 6, a further set of castor wheels37, 38 may be mounted on the hinged boom sections 23B, 24B in additionto the to the castor wheels 37, 38 on the main boom sections 23A, 24A.

The castors 37, 38 illustrated in FIGS. 11 and 12, may be mounted via aspindle 41 to the castor brackets 39, 40 which are fixed to rake booms23, 24, and/or to the the hinged boom sections 23B, 24B of the rakebooms 23, 24, using wheel mounts 52, 53. Further, castors 35, 36 may bemounted directly on the castor extensions 33, 34 via a spindle 41.However, it has been found that if the castors 35, 36, 37, 38 are leftto rotate freely about the spindle 41 axis, they become unstable whenthe V-rake 10, 110, 210 is moving at high speeds while being relocated.A braking mechanism 43 is therefore fixed to the spindle 41. The brakingmechanism 43 includes a brake disk 45, which rotates with the spindle41, and lower and upper plates 47, 49 positioned so as to rub againstthe disk 45 between them. The pressure of the plates 47, 49 on the disk45 is adjusted by a tightening screw 51, which passes through the plates47, 49 into the castor extensions 33, 34 (not shown) or the brackets 39,40.

As shown in FIGS. 1 to 10, in order to control the position of the booms23, 24 with respect to the tow beam 12, a control mechanism 61 isconnected to the booms 23, 24 and slidably connected to the main beamsection 14. The control mechanism 61 includes riser arms 63, 64 fixed tothe booms 23, 24 and shaped to slant upwardly and inwardly towards thecenter of the V-rake 10, 110, 210. Using ball joints, pairs of scissorarms 65, 67 and 66, 68 are connected at one end to shafts 69, 70, whichpass through riser arms 63, 64. The other ends of scissor arms 65, 66are connected using ball joints to a sleeve 71 that slides on the mainbeam section 14, while the other ends of scissor arms 67, 68 areconnected using ball joints to a sleeve 72 that also slides on the mainbeam section 14. A hydraulic cylinder 73, which is fixed between sleeve71 and the main beam section 14, operates to move the sleeve 71 towardsthe back of the V-rake 10, 110, 210 to close the rake placing it in itstransport position, or to move the sleeve 71 towards the front of theV-rake 10, 110, 210 to place the rake in its operating position. Assleeve 71 is moved back or forth, the sleeve 72 is also forced to moveforth or back as well. Alternately, the cylinder may be connectedbetween sleeve 72 and the main beam section 14.

A number of rake wheels 25, 26 are mounted on the inside of the rakebooms 23, 24 and their extensions 31, 32 using wheel arms 27, 28 whichare pivotally connected to the rake booms 23, 24 and their extensions31, 32 and controlled in height by springs assemblies 81, 82 inconjunction with wheel lift rods 83, 84. Conventional rake wheels 25, 26may be used with the present V-rake 10. Alternately rake wheels 25, 26in accordance with the present invention, which are described inconjunction with FIGS. 25 to 29, may also be used.

The spring assemblies 81, 82 are connected to wheel lift rods 83, 84 byclips 85, 86 and the rods 83, 84 are mounted on the booms 23, 24 andextensions 31, 32 using plastic grommets 87, 88 so that the rods 83, 84may be moved linearly along the booms 23, 24 and extensions 31, 32 usingwheel lift hydraulic cylinders 89, 90. A mechanical adjustment mechanism91, 92, as shown in FIG. 13, may also be connected between the wheellift hydraulic cylinders 89, 90 and the booms 23, 24 to assure the idealoperating weight of the wheels 25, 26 with respect to the terrainsurface. The adjustment mechanism 91, 92 may consist of a threaded rod93 passing through a bracket 94 fixed to the boom 23, 24 with a nut 95on the rod 93 on either side of the bracket 94. Using the nuts 95, therod 93 may be adjusted longitudinally along the length of the boom 23,24.

When the rake booms 23, 24 include hinged boom sections 23B, 24B thatare connected to the main boom sections 23A, 24A using knuckle hinges100, it is necessary to include two pivot points in both of the wheellift rods 83, 84. One of the pivot points would be located in the rods83, 84 at a point just above the knuckle 100 axis when the rake wheels25, 26 are lowered in their operating position and the other of thepivot points would be located in the rods 83, 84 at a point just abovethe knuckle 100 axis when the rake wheels 25, 26 are raised for theirtransport position.

Alternately, as shown in FIGS. 14 and 15, the wheel lift rods 83, 84 maybe slidably terminated in a bracket 101, 102 at the front end of therake boom sections 23A, 24A at the knuckle hinge 100. Additional wheellift rods 103, 104 may be used to control the rake wheels 25, 26 thatare connected to the hinged boom sections 23B, 24B and the boomextensions 31, 32. The positioning of rods 103, 104 will be controlledby a similar mechanism as rods 83, 84. Wheel lift hydraulic cylinders89, 90 are connected between rods 103, 104 and a mechanical adjustmentmechanism 91, 92. The adjustment mechanism 91, 92 may consist of athreaded rod 93 passing through a bracket 94 fixed to the arm 23B, 24Bwith a nut 95 on the rod 93 on either side of the bracket 94. Using thenuts 95, the rod 93 may be adjusted longitudinally along the length ofthe arm 103, 104.

In view of the weight of the rake wheels 25, 26 used in wheel rakes 10,110, 210, a spring assembly 81, 82 is required for each rake wheel 25,26 to maintain a predetermined ideal wheel weight on the ground surfaceto prevent the rake wheel 25, 26 from digging into the ground. Thespring assembly 81, 82 also has the function of assisting a wheel 25, 26to rise over bumps or rocks on the ground surface, as well as to preventa wheel 25, 26 from abruptly dropping into a depression in the groundsurface. Further, the spring assemblies 81, 82 operate in conjunctionwith wheel lift rods 83, 84 to move the wheels 25, 26 between theiroperating and transport positions.

Either the tension spring assembly 181 shown in FIGS. 16 and 17 or thecompression spring assembly 281 shown in FIG. 18 may be used as thespring assembly 81 for the V-rakes 10, 110, 210 illustrated in FIGS. 1to 10. Spring assembly 181, 281 is attached between the wheel arm 27 andthe wheel lift rod 83, 103 on the left side of the V-rake 10, 110, 210.The spring assembly 182, 282 between the wheel arm 28 and wheel lift rod84, 104 on the right side of the V-rake 10, 110, 210 is constructedsimilarly to, but as a mirror image of, the left side spring assembly181, 281, and operates in a similar manner.

Making reference to FIGS. 16 and 17, the tension spring assembly 181 ismounted between the wheel arm 27, which is connected to the rake wheel25 at one end and which pivots using a pin 121 that is attached to therake boom 23, or an extension 31. The tension spring assembly 181 isfurther connected to the wheel lift rod 83, 103 using a clip 85. Atension spring 122 is mounted on a rod 123 using plastic inserts 124,125, which screw into the ends of the spring 122, such that the rod 123can move freely through the inserts 124, 125. One end of the rod 123 isthreaded and is screwed into a yoke 126 that connects to the clip 85.This permits the height of each wheel 25 to be adjusted individually. Astopper 127 is fixed to the rod 123 a predetermined distance from theyoke 126 allowing the plastic insert 124 to slide on the rod 123 betweenthe stopper 127 and the yoke 126. This will permit a wheel 25 to risewhen it moves over a bump. The other end of the rod 123 extends out ofthe end of the spring 122 somewhat at the plastic insert 125. However, astopper 128 is placed at the end of rod 123 such that the plastic insert125 will not slide past the end of the rod 123. This is required so thatthere is a limit to the distance that a wheel 25 may drop as it passesover a depression. An arm 129, which is fixed in length, connects thewheel lift arm 27 to the plastic insert 125. The arm 129 preferably hasa yoke or clevis 130, which is pivotally connected to the plastic insert125 using pins 131. The base 132 of the clevis 130 is in the form of ashaft that is able to turn in a cylinder 133 and is fixed therein sothat there will be no longitudinal movement. Cylinder 133 is fixed tothe wheel lift arm 27.

In operation, the wheel 25 is lowered by moving the wheel lift rod 83,103 in the direction of arrow 134W, placing the spring mechanism 181 inthe working position shown in FIGS. 16 and 17, where just sufficienttension remains on the spring 122 to permit the wheel to be turned bythe surface of the ground. In this position, if the wheel 25 moves overa bump, tension is released by the lifting wheel 25; if the wheel goesover a depression, tension is increased by the dropping wheel 25. Tolift the wheel 25 to the transport position, the wheel lift rod 83 ismoved in the direction of arrow 134T, placing more tension on the spring122 to lift the wheel 25.

Making reference to FIG. 18, the compression spring assembly 281 ismounted between the wheel arm 27, which is connected to the rake wheel25 at one end and which pivots using a pin 141 that is attached to therake boom 23 or an extension 31. The compression spring assembly 281 isfurther connected to the wheel lift rod 83, 103 using a clip 85. Acompression spring 142 is mounted on a rod 143 using an insert 144having a plastic lining at one end and a fixed plug 145 at the otherend. Insert 144 is designed to permit it to slide freely on the rod 143.One end of the rod 143 is fixed to a yoke 146 that connects to the clip85. The insert 144 has an arm 147 extending from one side and curvedthrough an angle of approximately 70 degrees. It is pivotally connectedto an arm 148 that is perpendicular and fixed the wheel arm 27.

In operation, the wheel 25 is lowered by moving the wheel lift rod 83 inthe direction of arrow 149W, placing the spring mechanism 281 in theworking position shown in FIG. 18, where just sufficient compressionremains on the spring 142 to permit the wheel to be turned by thesurface of the ground. In this position, if the wheel 25 moves over abump, compression is released by the lifting wheel 25; if the wheel goesover a depression, compression is increased by the dropping wheel 25. Tolift the wheel 25 to the transport position, the wheel lift rod 73 ismoved in the direction of arrow 149T, placing more compression on thespring 142 to lift the wheel 25.

In the V-rake 10, 110, 210, the cut agricultural material in a field israked towards the center of the rake to form a windrow. As it isdesirable to have windrows of different widths depending on factors suchas the type of equipment that will be gathering the material and/or theyield of the material to be gathered, the V-rake 10, 110, 210, inaccordance with the present invention, has a back section 13 adapted toadjust the distance between the rake wheel assemblies 21, 22 at the backof the V-rake 10, 110, 210. FIG. 19 illustrates a mechanically adjustedback section 113 while FIGS. 20 to 22 illustrate a hydraulicallyadjusted back section 213. Though any one of these back sections 113,213 can be used with any one of the V-rakes 10, 110, 210, V-rake 10 isillustrated in FIGS. 1 to 3 with a back section 113 and V-rakes 110 and210 are illustrated in FIGS. 4 to 10 with a back section 213.

The back section 113, as shown in detail in FIG. 19, includes a firsthorizontal beam 150 that is fixed at the center of the beam 150 to thetow beam 12. The back section 113 further includes two vertical beams151 and 152, each fixed to second horizontal beams 153, 154, which abutat the center of the rear section 113. U-shaped channels 155, 156 whichare fixed to the first horizontal beam 150, hold the second horizontalbeams 153, 154 in close proximity to the first horizontal beam 150, yetpermitting the second horizontal beams 153, 154 to extend outward fromthe center. The back section 113 further includes oppositely threadedrods 159, 160 with ends fixed to devises 161, 162 that connect tobrackets 163, 164. Brackets 163, 164 are fixed to the second horizontalbeams 153, 154. A pipe 157 having inner opposite threads is screwed ontothe rods 159, 160. A ratchet 158 is used to rotate the pipe 157, therebymoving the rods 159, 160 into or out of the pipe 157 resulting in thevertical sections 151, 152 being moved inward or outward from the centerof the V-rake 10 to adjust the width of the windrow formed by the V-rake10.

Wheel assemblies 21, 22 each include single wheels 165 and 166 mountedon spindles 167, 168. The spindles 167, 168 are welded to flanges 169,170 that are fixed to the ends of the vertical beams 151, 152.

Brackets 171, 172 are located approximately midway up the vertical beams151, 152 so that the rake booms 23, 24 may be connected to the backsection 113 using 4-way knuckle joints 173, 174. The knuckle joints 173,174 permit the booms 23, 24 to pivot in the horizontal direction so thatthe V-rake 10 may be opened and closed, as well as to pivot in thevertical direction to permit the booms 23, 24 to follow the contour ofthe terrain without placing undue stress on the connection between thebooms 23, 24 and the back section 113.

The back section 213 illustrated in FIG. 20 to 23 is basically a U-framecomprising first and second horizontal beams 250, 251 with their endsfixed to two vertical beams 253, 254. As shown in FIGS. 22, the mainbeam section 14 of tow beam 12 is fixed to the back section 213, withthe beam 17 being connected to the first horizontal beam 250 and thetruss support 18 being connected to the second horizontal beam 251,which is vertically spaced from the first horizontal beam 250. Further apair of braces 255, 256 are connected between the beam 17 by anadjustable bracket 257 and the second horizontal beam 251 at fixedbrackets 259, 260.

The rake booms 23, 24 are attached to the vertical beams 253, 254 usingpivot boxes 261, 262 of the type shown in FIG. 21. The pivot boxes 261,262 are attached to the vertical beams by brackets 263, 264 where theyare permitted to pivot about vertical axes 265, 266. The rake booms 23,24 are connected to the other end of the pivot boxes 261, 262 by pins267, 268 such that they are able to pivot about the axis of pins 267,268 relative to the pivot boxes 261, 262. As can be seen in FIG. 23, thebooms 23, 24 may pivot into an open or closed position about pins 267,268, and in addition, the pivot boxes 261, 262 may be pivoted about axes265, 266 to move the back ends of the rake booms 23, 24 either closertogether or further apart, without changing the relative positions ofthe rake wheel assemblies 21, 22. The rake wheel assemblies 21, 22follow in the same track all of the time.

In the present embodiment, the positioning of the pivot boxes 261, 262is hydraulically controlled. The structure 269 for implementing thecontrol function is best shown in FIGS. 22 and 23. Structure 269includes a horizontal beam 270, which is held at the center of the backsection 213 below horizontal beam 251 and in between vertical beams 253,254, by an arm 271, which is fixed to the horizontal beam 25.0. A sleeve272 is mounted on the horizontal beam 270 such that it is free to slidealong the beam 270. The beam 270 may include a clevis 273 for receivinga pin 274 in the sleeve 272, which would limit the distance of travel ofthe sleeve 272. Further, a hydraulic cylinder 275 has one end pivotallyconnected to the sleeve 272 and the other end connected to a truss plate19, in order to control the movement of the sleeve 272. To control theposition of the rake booms 23, 24, linkages 277, 278 are pivotallyconnected between the sleeve 272 and the pivot boxes 261, 262respectively.

In operation, when the sleeve 272 is in its forward position, theposition shown in FIG. 23, the back ends of the booms 23, 24 are thefurthest apart, which would result in a wide windrow. Alternately, whenthe sleeve 272 is in its furthest rearward position, linkages 277, 278bring the ends of booms 23, 24 closer together, which would result in anarrow windrow. It is noted that the windrow width can therefore beadjusted without changing the distance between the back wheel assemblies21, 22. Also, the hydraulic cylinder 275 may be controlled to obtain awindrow width anywhere in between the extremes of a narrow and a widewindrow.

FIGS. 4 and 6 illustrate examples of V-rakes 110, 210 in their operatingposition with the booms 23, 24 positioned to provide the widest possiblewindrow, while FIGS. 5 and 7 illustrate examples of V-rakes 110, 210 intheir operating position with the booms 23, 24 positioned to provide thenarrowest possible windrow. It is to be noted that, since fixed riserarms 63, 64 represent pivot points at shafts 69, 70 for rake booms 23,24, the opening or the distance between the ends of booms 23, 24 at thefront of an open V-rake 110, 210, is greater when the back ends of booms23, 24 are closer together, then when the back ends of booms 23, 24 arefurther apart. In other words, the swath covered by a V-rake 110, 210that is producing narrow windrows is greater then the swath covered by aV-rake 110, 210 that is producing a wide windrow.

In addition, as shown in FIG. 8 for the transport position, the backends of booms 23, 24, which are as apart from one another that they canbe, are still within the wheels assemblies 21, 22. Therefore, the wheelassemblies 21, 22 dictate the overall width of the V-rake 10, 110, 210in transport position. It is further noted that the booms 23, 24 may bebrought closer together, both at the back and the front of the V-rake10, 110, 210. In order to stabilize the V-rake 10,110, 210 further whilein transport, a pair of transport arms 105, 106 may be pinned betweenthe tow beam gooseneck section 15 and the castor extensions 33, 34.

As shown in FIG. 20, the back wheel assemblies 21, 22 are fixed to thelower ends of vertical beams 253, 254. However, as shown in FIGS. 20, 23and 24, rather then having single wheels, each assembly 21, 22 includesa pair of tandem wheels 281, 283 and 282, 284; wheels 281, 282 being theouter wheels and wheels 283, 284 being the inner wheels. In addition,the wheels 281, 283 and 282, 284, are mounted on a carriage 285, 286which is pivotally connected to the ends of vertical beam 253, 254. Thecarriage 285, 286 is constructed such that the outer wheels 281, 282 arepositioned towards the back of the back section 213, whereas the innerwheels 283, 284 are positioned towards the front of the back section213. This arrangement has the advantage that wheels 283, 284 are locatedclose to, but behind the back rake wheels 25, 26 whether the V-rake 110,210 is positioned to produce wide windrows as shown in FIG. 23, ornarrow windrows. This arrangement prevents the wheels 283, 284 fromrunning over material in the windrow as it settles with the passing ofthe last rake wheels 25, 26. Since, the back wheels 281, 282 are furtherapart, they also will not run over the settled windrow.

Further, as shown in FIG. 24, the distance “A” between back wheel 281,282 spindle mount 291 and the pivot mount 293 for the carriage 285, 286is shorter than the distance “B” between front wheel 283, 285 spindlemount 295 and the pivot mount 293 for the carriage 285, 286. In thisway, less ground pressure is applied to the front wheels 283, 284, whichtend to float, preventing them from being pressed into the ground inrough fields.

Rake wheel assemblies 300, 310 in accordance with the present inventionare illustrated in FIGS. 25 and 26. Wheel assembly 300 in FIG. 25 isidentical to wheel assembly 310 in FIG. 26 except that one is a mirrorimage of the other. These wheel rake assemblies 300, 310 are for use onthe left and the right sides respectively of the wheel rake 10, 110,210. The rake wheel assembly 300, 310 includes a center disk 311 havinga predetermined radius and holes 312 substantially equally spaced aroundits outer edge or periphery, and an outer ring 313 having an equalnumber of substantially equally spaced holes 314 around its periphery.The ring 313 has a substantially rectangular cross-section with thelarger side facing the center of the ring 313. The center disk 311 isadapted to be mounted on a hub 200, as shown in FIG. 17. The hub 200,which passes through an opening 323 in the center disk 311, includes aflange on which are located bolts that pass through holes 324 to befastened with nuts in a conventional manner.

Rake tines 315, which may take on various conventional shapes such asthe Z-shape that is illustrated, slide through the holes 314 in theouter ring 313 of the rake wheel assembly 300, 310 and are bolted to theheavier center disk 311. A loop 316 is formed into the end of the raketine 315 to accept a bolt 317. Holes 312 are preferably square holes forreceiving carriage bolts 317 that will be prevented from turning whencorresponding nuts are tightened. A bolt 317 is placed in each hole 312to receive the loop 316 of a single tine 315 and is fixed in place by anut. The loop 316 wraps around the bolt 317 to prevent the tine 315 fromjarring loose under heavy raking conditions. One feature of the rakewheel assembly 300, 310 is that rake tines 315 are individually fixed tothe center disk 311 of the rake wheel assembly 300, 310. This featuresimplifies assembling the rake wheel assembly 300, 310 and also thereplacement of a tine 315.

Another feature of the rake wheel assembly 300, 310 in accordance withthe present invention is an integrated windguard 318. The windguard 318is an annulus or disk 319 made from a light gauge galvanized metal. Theradius of an outer periphery 330 of the annulus 319 is substantiallyequal to the inner radius of the outer ring 313 and an inner radius 331of the annulus 319 is smaller than the radius of the center disk 311.The windguard 318 further has tabs 320 equally spaced around theperiphery of the annulus 319. The tabs 320 are substantiallyperpendicular to the surface of the annulus 319 and fit inside the outerring 313 of the rake wheel assembly 300, 310. The tabs 320 further haveholes 321 that line up with the holes 314 in the outer ring 313. In thisparticular embodiment, there is a tab 320 adjacent every second hole 314in the outer ring 313; however, tabs 320 may be located at every hole314 or even less frequently such as at every fourth hole 314.

The annulus 319 further includes holes around its inner periphery suchthat the holes match the holes 312 in the center disk 311. In this way,the windguard 318 is attached to the center disk 311 of the rake wheelassembly 300, 310 by the same bolts 317 that hold the rake tines 315 tothe center disk 311. To add rigidity to the annulus 319, indentations322 are stamped into it.

FIGS. 27 to 29 show the assembly procedure for the rake wheel assembly300, 310. The first step is to align the center disk 311, windguard 318,and outer ring 313 in the 12:00 o'clock position as shown. In FIGS. 27and 28, a straight rod 325 is used as a reference. When in the 12:00o'clock position, the rod 325 will pass over the bolt hole loop 316 onthe tine 315. In this position, the rake tine 315 must pass through theouter ring 313 two holes 314 to the left of the rod 325. This gives theorientation of the tine 315 on the rake wheel assembly 300, 310. If therake wheel assemblies 300, 310 are to be used on a “V” style rake, bothleft and right rake wheel assemblies 300, 310 are required. Assemblingboth rake wheel assemblies 300, 310 is the same except that the firsttine 315 must pass through a hole 314 two holes 314 to the right ofvertical rod 325 for the opposite rake wheel assembly 300, 310, as shownin FIG. 28. The rake wheel assemblies 300, 310 illustrated in FIGS. 26and 27 would be used on the right side of a “V” style rake and the rakewheel assemblies 300, 310 illustrates in FIGS. 26 and 28 would be usedon the left side of a “V” style rake.

FIG. 29 illustrates how the remaining tines 315 are bolted in side byside to complete the rake wheel assembly 300, 310. With this method, thewindguard 318 is securely attached to the rake wheel assembly 300, 310with no welding or painting required. Because the windguard 318 isintegrated into the rake wheel assembly 300, 330, the windguard 318 addsstrength and durability to the rake wheel assembly 300,330.

Because the windguard 318 gives the front of the rake wheel assembly300, 310 a smooth surface, the raked material has nothing to catch ontoand therefore it will not wrap, and the windguard 318 prevents the rakedmaterial from wrapping on the rake wheel assembly 300, 310 in windyconditions.

While the invention has been described according to what is presentlyconsidered to be the most practical and preferred embodiments, it mustbe understood that the invention is not limited to the disclosedembodiments. Those ordinarily skilled in the art will understand thatvarious modifications and equivalent structures and functions may bemade without departing from the spirit and scope of the invention asdefined in the claims. Therefore, the invention as defined in the claimsmust be accorded the broadest possible interpretation so as to encompassall such modifications and equivalent structures and functions.

1. A V-rake comprising: a tow beam having a front end adapted to beconnected to a towing vehicle and a back end; a back section connectedto the back end of the tow beam; first and second rake booms each havinga front end and a back end, the back end of the first rake boom beingpivotally connected to a first pivot box, the back end of the secondrake boom being pivotally connected to a second pivot box, the first andsecond pivot boxes pivotally connected to the back section such that thefront ends of the booms can be swung between a transport positionwherein the rake booms are generally parallel to the tow beam and anoperating position wherein the rake booms are positioned at apredetermined angle to the tow beam; a number of rake wheels mounted oneach of the rake booms on a side of the boom nearest to the tow beam,the rake wheels adapted to move vertically with respect to the rakeboom; the first and second boxes each having a predetermined widthbetween one side and another side of the pivot box, the one side of thefirst pivot box being pivotally connected to the back section and thefirst rake boom being pivotally connected to the other side of the firstpivot box, the one side of the second pivot box being pivotallyconnected to the back section and the second rake boom being pivotallyconnected to the other side of the second pivot box; and a pivot boxcontrol mechanism for moving the other sides of the pivot boxes towardsand away from one another to change the distance between the back endsof the rake booms.
 2. A V-rake as claimed in claim 1 wherein the backsection comprises: first and second vertical beams each having lower andupper ends; a horizontal beam fixed between the upper ends of the firstand second vertical beams; wherein the one side of the first pivot boxis pivotally connected to the first vertical beam between the lower andupper ends and the one side of the second pivot box is pivotallyconnected to the second vertical beam between the lower and upper ends.3. A V-rake as claimed in claim 2 wherein the pivot box controlmechanism comprises: a horizontal control beam fixed between the firstand second vertical beams and below the horizontal beam; a sleeveslidably mounted on the horizontal control beam; first and secondlinkages pivotally connected between the sleeve and the other sides ofthe pivot boxes; and a hydraulic cylinder connected between the sleeveand the tow beam to control the movement of the sleeve along thehorizontal control beam.
 4. A V-rake as claimed in claim 2 wherein theback section comprises a wheel assembly for supporting the back section.5. A V-rake as claimed in claim 4 wherein the wheel assembly comprises afirst wheel rotatably fixed to the lower end of the first vertical beamand a second wheel rotatably fixed to the lower end of the secondvertical beam.
 6. A V-rake as claimed in claim 4 wherein the wheelassembly comprises a first set of tandem wheels pivotally fixed to thelower end of the first vertical beam and a second set of tandem wheelspivotally fixed to the lower end of the second vertical beam.
 7. AV-rake as claimed in claim 6 wherein each set of tandem wheelscomprises: a wheel carriage; and a pair of wheels mounted by axles ontothe carriage such that the wheels are in parallel and staggered front toback relative to one another, wherein the front wheel is positioned onthe inside of the V-rake and the back wheel is positioned on the outsideof the V-rake.
 8. A V-rake as claimed in claim 7 wherein the carriage ispivotally fixed to the vertical beam at a pivot point, wherein adistance between the pivot point and the axle of the front wheel isgreater than a distance between the pivot point and the axle of the backwheel.
 9. A V-rake as claimed in claim 1 comprising a rake wheel arm foreach of the rake wheels, having one end adapted to be pivotallyconnected to the rake boom and another end having a spindle forreceiving a rake wheel of the rake wheels.
 10. A V-rake as claimed inclaim 9 comprising a spring assembly connected to the rake wheel arm andadapted to permit the rake wheel to move vertically with respect to therake boom.
 11. A V-rake as claimed in claim 10 comprising a wheel liftrod connected to the spring assembly for raising and lowering the rakewheel.
 12. A V-rake as claimed in claim 11 wherein the wheel lift rod ishydraulically actuated.
 13. A V-rake as claimed in claim 10 wherein thespring assembly includes a tension spring.
 14. A V-rake as claimed inclaim 10 wherein the spring assembly includes a compression spring. 15.A V-rake as claimed in claim 10 wherein the spring assembly comprises: acompression spring having first and second ends; a plug fixed to thefirst end of the spring; an insert fixed to the second end of thespring, the insert having an arm extending from the insert; a rod havinga first end and a second end, positioned within the compression spring,wherein the first end is fixed to the plug and the second end extendsout of the second end of the spring through the insert, such that theinsert slides freely on the rod, the second end of the rod adapted to beconnected to a mechanism to control its movement; and a further armhaving first and second ends, the first end fixed to the rake wheel armand the second end pivotally connected to the insert arm, whereby thecompression spring permits the rake wheel to move vertically to follow aterrain contour.
 16. A V-rake as claimed in claim 11 wherein the springassembly comprises: a compression spring having first and second ends; aplug fixed to the first end of the spring; an insert fixed to the secondend of the spring, the insert having an arm extending from the insert; arod having a first end and a second end, positioned within thecompression spring, wherein the first end is fixed to the plug and thesecond end extends out of the second end of the spring through theinsert, such that the insert slides freely on the rod, the second end ofthe rod is connected to the wheel lift rod; and a further arm havingfirst and second ends, the first end fixed to the rake wheel arm and thesecond end pivotally connected to the insert arm, whereby thecompression spring permits the rake wheel to move vertically to follow aterrain contour.
 17. A V-rake as claimed in claim 1 wherein the rakewheel comprises: a center disk having a predetermined radius adapted tobe mounted on a hub; a number of rake tines; an outer ring having asubstantially greater radius then the center disk and having holes atleast equal to the number of rake tines, the holes being spaced aboutand passing radially through the outer ring, whereby each of the tinesis positioned in a hole in the outer ring with one end of each tinefixed to the center disk.
 18. A V-rake as claimed in claim 17 whereinthe center disk has holes at least equal in number to the rake tinesspaced about its periphery for receiving fasteners to individually fixthe tines to the center disk.
 19. A V-rake as claimed in claim 17wherein the outer ring has a substantially rectangular cross-sectionwith a larger side of the rectangular cross-section facing the center ofthe outer ring.
 20. A V-rake as claimed in claim 17 comprising awindguard positioned between the center disk and the outer ring.
 21. AV-rake as claimed in claim 20 wherein the windguard comprises an annulushaving an outer radius approximately equal to the radius of the outerring and an inner radius smaller than the radius of the center disk soas to overlap with the center disk, an inner periphery of the annulushaving holes that match with holes in the center disk, and an outerperiphery of the annulus having tabs with holes that match with some ofthe holes in the outer ring, the tabs being substantially perpendicularto the surface of the annulus, whereby rake tines are located in theouter ring holes and matching tab holes.
 22. A V-rake as claimed inclaim 21 wherein the holes in the center disk are at least equal innumber to the rake tines, spaced about its periphery for receivingfasteners to individually fix the tines and the windguard to the centerdisk.
 23. A V-rake as claimed in claim 20 wherein the windguard is alight gauge galvanized metal with stamped indentations.
 24. A V-rake asclaimed in claim 1 wherein the tow beam comprises: a main beam sectioncomprising the tow beam back end connected to the back section; agoose-neck section connected to the main beam section; and a hitchconnected to the goose neck section.
 25. A V-rake as claimed in claim 24wherein the main beam section and the goose neck sections each include abeam, a truss support and truss plates connecting the beam to the trusssupport.
 26. A V-rake as claimed in claim 1 wherein the front end ofeach rake boom comprises a castor wheel for supporting the rake boom.27. V-rake as claimed in claim 26 wherein the rake booms include castorextensions fixed to the front end of the booms for mounting the castorwheels.
 28. V-rake as claimed in claim 1 wherein the rake booms includeboom extensions for elongating the rake booms.
 29. A V-rake as claimedin claim 28 wherein at least one additional rake wheel is mounted oneach of the boom extensions.
 30. A V-rake as claimed in claim 1 whereinthe rake booms include a hinged section for providing flexibility to therake boom.
 31. A V-rake as claimed in claim 30 wherein a castor wheel ismounted on each of the hinged sections of the rake booms.
 32. A V-rakeas claimed in claim 26 wherein the castor wheel includes a brakingmechanism to stabilize the castor wheels.
 33. A V-rake as claimed inclaim 1 further comprising a control mechanism connected between the towbeam and the booms to pivot the booms between the operating position andthe transport position.
 34. A V-rake as claimed in claim 33 wherein thecontrol mechanism for positioning the rake booms comprises: a firstsleeve slidably mounted on the tow beam towards the back end of the towbeam; a second sleeve slidably mounted on the tow beam towards the frontend of the tow beam; a first pair of scissor arms pivotally connectedbetween the first and second rake booms and the first sleeve; a secondpair of scissor arms pivotally connected between the first and secondrake booms and the second sleeve; and a sleeve moving mechanism forchanging the distance between the first and the second sleeve.
 35. AV-rake as claimed in claim 34 wherein the sleeve moving mechanism is ahydraulic cylinder having one end fixed to the tow beam and another endconnected to one of the first sleeve and the second sleeve.
 36. A V-rakeas claimed in claim 34 herein the sleeve moving mechanism is a hydrauliccylinder having one end connected to the first sleeve and another endconnected to the second sleeve.
 37. A V-rake comprising: a tow beamhaving a front end adapted to be connected to a towing vehicle and aback end: a back section connected to the back end of the tow beam;first and second rake booms each having a front end and a back end, theback end of each rake boom being pivotally connected to the back sectionsuch that the front ends of the booms can be swung between a transportposition wherein the rake booms are generally parallel to the tow beamand an operating position wherein the rake booms are positioned at apredetermined angle to the tow beam; a number of rake wheels mounted oneach of the rake booms on a side of the boom nearest to the tow beam,wherein the rake wheels are adapted to move vertically with respect tothe rake boom; and wherein the back section comprises: first and secondvertical beams each having lower and upper ends, the rake booms beingpivotally connected to the vertical beams between their lower and upperends; a first horizontal beam having one end fixed to the upper end ofthe first vertical beam and a second horizontal beam having one endfixed to the upper end of the second vertical beam such that the otherends of the horizontal beams are positioned end to end; a thirdhorizontal beam positioned adjacent and aligned vertically with thefirst and second horizontal beams, the tow beam being fixedsubstantially to the center of the third horizontal beam; a widthcontrol mechanism connected between the third horizontal beam and thefirst and second horizontal beams adapted to move the first and secondhorizontal beams in a direction parallel to the third horizontal beam tochange the distance between the first and second vertical beams.